Leafhoppers (Homoptera: Cicadellidae) Associated with Potatoes in Alaska: Species Composition, Seasonal Abundance, and Potential Phytoplasma Vectors

Abstract

Leafhopper transmitted phytoplasma diseases are an emerging problem for potato and vegetable producers in the conterminous US. Due to its geographical isolation and climatic constraints, Alaska is considered relatively free of diseases and insect pests; therefore growers in the state are exploring the potential of producing seed potato for export. However, the biology of agricultural insect pests in the circumpolar region is lacking or poorly understood. Research conducted from 2004 to 2006 in the main potato (Solanum tuberosum L.) production areas of Alaska resulted in the identification of 41 leafhopper species associated with agricultural settings. Twenty species were identified from sweep net samples and adhesive cards in association with potato. Two species, Davisonia snowi (Dorst) and Macrosteles fascifrons (Stål), made up approximately 60% of the total number of individuals collected, representing 34 and 26%, respectively. Both species, M. fascifrons and D. snowi generally arrived in fields by late May to early June and numbers peaked by late June to July, but in all years M. fascifrons populations peaked earlier than D. snowi. Twenty-three percent of the specimens were immature or could not be identified. Three of the species collected [Balclutha punctata (Fabricius), M. fascifrons, and Scaphytopius acutus (Say)] are known vectors of phytoplasmas of potatoes and other agricultural crops or have the potential to cause mechanical damage to potatoes. This report represents the first extensive study of cicadellids from potatoes in Alaska.Resumen Las enfermedades causadas por fitoplasmas trasmitidas por saltahojas son un problema emergente para los productores de hortalizas en los Estados Unidos de América. Debido a su ubicación geográfica y restricciones climáticas, Alaska es considerada relativamente libre de plagas; por tal razón los productores de papa en el estado exploran la posibilidad de producir semilla de papa para exportación. Sin embargo, la biología de las plagas agrícolas en las zonas circumpolares es poco conocida o inexistente. Investigación realizada de 2004 al 2006 en las áreas de mayor producción de papa (Solanum tuberosum L.) en Alaska resultó en la identificación de 41 especies de saltahojas asociadas a sistemas agrícolas. Veinte especies fueron identificadas de muestras capturadas con red entomológica y trampas adhesivas en asociación al cultivo de la papa. Dos especies, Davisonia snowi (Dorst) y Macrosteles fascifrons (Stål) constituyeron aproximadamente el 60% del total de especimenes capturadas, representando el 34 y 26%, respectivamente. Ambas especies, M. fascifrons y D. snowi, generalmente aparecieron en los campos a final de Mayo o inicio de Junio y alcanzaron su mayor número a final de Junio o inicio de Julio, pero en todos los años las poblaciones de M. fascifrons alcanzaron su punto máximo antes que D. snowi. Veintitrés por ciento de los especimenes fueron insectos inmaduros o no pudieron ser identificados. Tres de las especies recolectadas [Balclutha punctata (Fabricius), M. fa...

Bumble Bees (Hymenoptera: Apidae: Bombus spp.) of Interior Alaska: Species Composition, Distribution, Seasonal Biology, and Parasites

“…Although no published reports are available on bumble bee population dynamics in Alaska's major agricultural areas to compare with our results, working with other taxa, Pantoja et al (Pantoja et al 2009, Pantoja et al 2010b, Pantoja et al 2010a) reported a similar pattern of higher relative densities of leafhoppers (Cicadellidae) and wireworms (Elateridae) in Delta Junction relative to Fairbanks and Palmer. Pantoja et al (Pantoja et al 2009, Pantoja et al 2010a, Pantoja et al 2010b) suggested that the differences in relative leafhopper and wireworm densities were associated with climatic differences, cropping histories, habitat availability, or agronomic practices.…”

“…Pantoja et al (Pantoja et al 2009, Pantoja et al 2010a, Pantoja et al 2010b) suggested that the differences in relative leafhopper and wireworm densities were associated with climatic differences, cropping histories, habitat availability, or agronomic practices. Bumble bee diversity and abundance can be affected by the availability of floral resources and nest sites, climatic conditions, presence of invasive species, habitat fragmentation, parasitic spillover, urbanization, competition, and the use of pesticides (Cane and Tepedino 2001,Roubik 2001, Goulson et al 2008).…”

Sustainable Agriculture for Alaska and the Circumpolar North: Part II. Environmental, Geophysical, Biological and Socioeconomic Challenges

“…However, their presence has been substantial enough to warrant decades of research. The bulk of animal pest research addresses insects, such as aphids or flies, which are common in the circumpolar North (Johansen, 1999;Johansen and Meadow, 2006;Pantoja et al, 2010b) and have affected Alaskan agriculture.…”

Sustainable Agriculture for Alaska and the Circumpolar North: Part III. Meeting the Challenges of High-Latitude Farming

“…There are some known challenges in controlling pests that infiltrate Alaskan farms (Stevenson et al, 2014a), although knowledge of agricultural insect pests, weeds, and diseases in the circumpolar region is lacking, and their occurrence and biology are poorly understood (Pantoja et al, 2009(Pantoja et al, , 2010a. Furthermore, agrochemicals used to kill pests, weeds, and disease can linger in the soils of cold environments longer than in warmer areas because the activity of soil bacteria to degrade them is generally slower in colder areas.…”

“…Research conducted from 2004 to 2006 in the main potato production areas of Alaska resulted in the documentation of species composition, abundance, and incidence of pests-for example, 41 leafhopper species, associated with agricultural settings-and the best time to sample them (Pantoja et al, 2009). The information on aphid abundance can be used to move planting dates to avoid aphid incidence, although because of the short growing season, it is not known if this practice will be feasible in Alaska.…”